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Chapter 10: Ecological Restoration Restoration • New field of developed w/in the science of ecology. – Goal = return damaged to some set of conditions considered functional, sustainable and “natural”. • Restore to what?

Balance of Balance of Nature

• Predominant belief that left undisturbed an • Twentieth century ecologist formalized the would achieve a single condition that would persist indefinitely. belief in the balance of nature • Major tenets of this belief – Climate state – steady-state stage that would – 1. Nature undisturbed achieves a permanency of form persist indefinitely and structure that persists indefinitely • Maximum biological diversity – 2. If it is disturbed and the disturbing force removed, • Maximum storage of chemical element nature returns to exactly the same permanent state. • Maximum biological diversity – 3. In this permanent state of nature, there is a “great chain of being” with a place for each creature.

Boundary Waters Canoe Area Balance of Nature Wilderness • Since the second half of the 20th century • 400,000 hectares in N Minnesota designated ecologist have learned that nature is not as wilderness constant. – Closed to logging and other direct – All ecosystems undergo change • Area has a natural history of fire – Species adapted to and need change – On average area burns once a century • Dealing with change poses questions of – When they occur at natural rate they have value beneficial effects – Controlling and managing fire – Landscape depends on change (dynamic)

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Goals of Restoration Goals of Restoration

• Frequently accepted that restoration means • Science tells us what nature has been and restoring an ecosystem to its historical what it could be. range of variation and to an ability to • Our values determine what we want nature sustain itself and its crucial functions to be. – Cycling of chemical elements – There is no single perfect condition. – The flow of energy – Maintenance of biological diversity

What Needs to be Restored?

• Ecosystems of all types have undergone degradation and need restoration. • Once again discussions about restoration involves values.

Wetland, Rivers, and Streams

• Estimated that CA has lost 90% of its wetlands. – The US about 50% • Kissimmee River in Florida – Channelized to provide ship passage – Now under going restoration at cost of several hundred million dollars

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Prairie Restoration Prairie Restoration

• Prairie once occupied more land in US than • Area along road ways not plowed any other kind of ecosystem. – Narrow strips of native prairie remain – Only a few remnants remain – In Iowa 242,000 hectares of prairie along – Land converted to agriculture roadways • Two kinds of restoration – Reservoir for native plants – Intact prairie (never been plowed) – Used as send sources for other restoration – Previously plowed land more complicated to projects restore

The Process of • Recovery of disturbed ecosystems can occur naturally, through a process of ecological succession. • Primary succession – The initial establishment and development of an ecosystem where one did not exist previously Examples of primary succession • Secondary succession after a lava flow and at the edge of a receding glacier. – Reestablishment of an ecosystem following disturbance

Patterns of Succession

• When succession occurs it follows certain general patterns. – Three examples include dunes, bog and abandoned farm field

Secondary succession- from abandoned field to mature forest

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Dune Succession Dune Succession

• Sand dunes continually formed along sandy • Plants of early succession tend to be shores. – Small, grow well in bright light, and withstand – Then breached and destroyed by storms harshness of environment • After dune forms • Over time larger plants can become – First to be established are grasses established – Grass runners stabilize dunes – Eastern red cedar, eastern white pine – Other species seeds may germinate and become established – Beech and maple later on

Bog Succession

• A bog is an open body of water with surface inlets but no surface outlets. • Succession begins with – Sedge puts out floating runners – Wind blows particles into the mat of runners – Seeds that land on top don’t sink in the water and can germinate – Mat becomes thicker and shrubs and trees can grow

Bog Succession

• The bog also fills in from the bottom – The the shoreward end floating mat and sediment will meet, forming a solid surface. – Farther from shore all the vegetation is still floating

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Old-Field Succession

• A great deal of land cleared for farming in the 18th and 19th centuries – That land now allowed to go back to forest • Succession – The first plants to enter the farm land are small plants adapted to harsh and variable conditions. – After they are established larger plants move in.

General Patterns of Succession General Patterns of Succession

• Common element include the following – 3. A third stage in which larger plants, – 1. An initial kind of vegetation specially including trees, enter and begin to dominate the adapted to the unstable conditions. site. • Typically small – 4. A forth stage in which mature forest • Help stabilize physical environment develops. – 2. A second stage with plants still of small statute, rapidly growing, with seeds that spread rapidly.

General Patterns of Succession General Patterns of Succession

• Successional stages • In early stages of succession – Early (1 and 2), middle, and late – and biological diversity increase • Similar patterns seen with animals and other • In middle stages life-forms at each stage. – Gross production increase and net production – Species characteristic of early stage are called decrease pioneers – Organic material in soil increases, as does – Late-successional species tend to be slower- chemical element storage growing and longer-lived

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Succession and Chemical Cycling • Storage of chemical elements generally increases during progression from early to middle for two reasons. – 1.Organic matter stores chemical elements • As one increases the other will increase • Nitrogen fixation – 2. Presence of live and dead matter helps stop erosion.

Succession and Chemical Succession and Chemical Cycling Cycling • As general rule, the greater the volume of • The chemical storage capacity of soils varies w/ soil and the greater the % of organic matter average size of the soil particle. in the soil , the more chemical elements will – Large coarse particles, like sand, have a smaller total surface area and can store a smaller quantity of be retained. chemical elements. – Varies with average size of soil particles – Smaller particles, like clay, store greater quantity of chemical elements. • Soils store large quantities of c.e. but not as readily available as those in living organisms.

Succession and Chemical Cycling • The increase in chemical element does not continue indefinitely. • With no disturbance ecosystem will have a slow loss of stored chemical elements – Becoming depauperate

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Species Change in Succession

• Earlier and later species in succession may interact in three ways – Facilitation – Interference – Life history differences • If they don’t interact the result is chronic patchiness

Facilitation

• In the dune and bog the facilitators are the dune grass and floating sedge, respectively. – They prepare the way for other species • Knowing the role of facilitation helps w/ restoration – These plants can be planted first

Interference

• Certain early species interfere w/ the entrance of other species. – Grasses may form dense mats blocking other seeds from germinating. – Breaks in the mat allow other to be established

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Life History Differences Chronic Patchiness

• An example of life history differences is • Common in deserts seed dispersal. – Major shrub species grow in patches – Early-successsional species are readily – Patch persist for long period of time until next transported by wind or animals. disturbance. • Reach clearing sooner • Life tends to build up, aggrade – Late-successional species seeds take longer to • Non-biological processes tend to erode or travel and seedlings can tolerate shade. degrade. – In harsh environments degrading dominates and succession does not occur.

Applying Ecological Knowledge

• Undo mining damage in Great Britain – To remove toxic pollutants – Restore biological production – Restore attractiveness of landscape • Agricultural approach failed – Grasses soon died and land was barren again • Ecological approach has been successful – Planting early successional species

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